Materials needed:
*ITLC-Silica Gel Strip
*0.9% Saline
Scissors
Pencil/Pen
Counting tubes/vials
MCA or SCA or Scaler with scintillation well
*Alternative media and solvents may be suitable. Use of other solvents and medium must be validated before routine use.
Procedure:
1. See General QC Procedure. Spot the sample 1 cm from the end of strip.
2. To develop the strip, place it in saline.
3. Allow the solvent to migrate to the ink spot/line at top of the strip.
4. Remove strip from solvent.
5. Cut strip at cut line above origin.
6. Count each section of the strip. If using an MCA for counting, remember to adjust the region of interest to one appropriate for In-111.
Counts:
Top: contains free In-111
Bottom: contains the tagged drug
% free In-111 = (top counts)/(bottom counts + top counts) X 100
% tagged radiopharmaceutical = 100- % free In-111
USP Minimum Acceptable Purities:
Oncoscint 90%